The following weapons appear in the anime Trinity Blood:
Abel's Revolver (Colt SAA "Peacemaker")
The Colt Single Action Army Cavalry Model is used by Abel Nightroad (Krusnik-02) while in human form. In-universe the gun is referenced as Craft Albion Works Peacekeeper Model-51, and is said to be chambered for .38 caliber rounds.
Beretta 90TWO ("Jericho M13")
The character Tres "Gunslinger" Iqus carries a pair of customized Beretta 90twos as his main weapons, fitted with laser pointers integrated into the guide rods and loaded with silver bullets. The pistols are identified to be in universe as being "Jericho M13" pistols, which are claimed to be the "world largest personal handguns" firing the "13mm 512 Maxima Rounds". From the artwork looks to be single stack magazines. The muzzle flash emitted from these weapons takes the shape of a cross.
One of Count Carl's men uses a Ruger P89 on Sister Agnes.
Large caliber pistol
Leon uses a pistol that resembles a Leuchtpistole flaregun.
M203 grenade launcher
Esther uses a pistol that resembles a Cobray CM79LF 37mm Launcher that has been modified to have a telescoping stock and a short barrel.
Bulgarian Arsenal AR
Arsenal AR assault rifles are used in flashback during the first episode being used by human soldiers fighting against vampires.
The AK-101 assault rifles are used by City of Ishtawaan's police.
FN Model 1949
FN Model 1949 rifles are seen carried by Albion's royal guardsmen, who then fruitlessly use them against Cain Nightroad (Krusnik-01).
Vanessa uses a UZI, when attempting to kidnapping the Pope.
In the first episode, Tres "Gunslinger" uses a MG42 on a air ship.
General Dynamics GAU-19/A
In the first episode, a person in a armored battle suit has a three barrel machine gun as it's weapon, which look like a General Dynamics GAU-19/A.
Leon uses a rocket launcher that resembles a RPO-A 'Shmel' rocket launcher.
M79 grenade launcher
One of the terrorist uses a M79 grenade launcher, when kidnapping the Pope.
The Ishtawaan's police uses a flamethrower to burn down the church.